Syphilis Serology 1

Question 1

What is the causative agent of syphilis?

Answer 1

Treponema pallidum

Question 2

Signs and symptoms associated with the Early Primary stage syphilis

Answer 2

Chancre at site

Question 3

Signs and symptoms associated with the Late Primary Stage of syphilis

Answer 3

Chancre healing

Question 4

Signs and symptoms associated with the Secondary Stage of syphilis

Answer 4

Skin rash, mucous membrane lesions

Question 5

Signs and symptoms associated with the Early Latent Stage of syphilis

Answer 5

No symptoms

Question 6

Signs and symptoms associated with the Late Latent Stage of syphilis

Answer 6

No ssmptoms

Question 7

Signs and symptoms associated with the Tertiary Stage of syphilis

Answer 7

Systemic (cardiac, skeletal, CNS)

Question 8

Darkfield Examination of Syphilis:

- appropriate specimen for testing

Answer 8

Only direct exam for treponemes. Collected from lesions (chancres, rash)

Question 9

Darkfield Examination of Syphilis:

- procedure

Answer 9

Sample collected from lesions, and examined by dark field microscopy (looking for motility of treponemes)

Question 10

Darkfield Examination of Syphilis:

• appearance of a positive
• appearance of a negative

Answer 10

Positive: Treponemes move in a definite direction using corkscrew or spiraling motility.
Negative: Non-pathogenic ttreponemes move randomly with inchworm style motility

Question 11

Darkfield Examination of Syphilis:

- stages where this test is helpful

Answer 11

Primary and Secondary stages because of collection type (lesions)

Question 12

Darkfield Examination of Syphilis:

- technical factors that limit the usefulness

Answer 12

• useful only when lesions present
• cumbersome (warmth, time limit)
• difficult to tell pathogenic from non-pathogenic

Question 13

Why are VDRL and RPR called “non-treponemal” tests?

Answer 13

Tests are not testing for antibodies against treponemes, only anti-tissue antibodies

Question 14

What is the definition of cardiolipin

Answer 14

(antigen) non nitrogenous phospholipid found in many plant and animal tissues

Question 15

Definition of reagin

Answer 15

non-specific anti-tissue antibodies NOT antibodies agains treponemes

Question 16

Sensitivity of Non-treponemal tests during early primary stage of syphilis

Answer 16

Negative

Question 17

Sensitivity of Non-treponemal tests during late primary stage of syphilis

Answer 17

Positive (titers increasing)

Question 18

Sensitivity of Non-treponemal tests during secondary stage of syphilis

Answer 18

Postive (titers high)

Question 19

Sensitivity of Non-treponemal tests during early latent stage of syphilis

Answer 19

Positive (titers declining)

Question 20

Sensitivity of Non-treponemal tests during late latent stage of syphilis

Answer 20

Positive? (titers declining)

Question 21

Sensitivity of Non-treponemal tests during tertiary stage of syphilis

Answer 21

50% may revert to negative

Question 22

What diseases may produce falsely positive results in the non-treponema tests for syphilis?

Answer 22

Other disease states/conditions have these antibodies (ex. pregnancy) The test can be too sensitive which leads to biological false positives.

Question 23

How are non-treponemall tests used to monitor treatment of syphilis

Answer 23

Useful because once treated successfully the disease goes away (you can get it again!) so you can monitor successful treatment

Question 24

How are non-treponemal tests used to identify re-infected with syphilis

Answer 24

Reagin antibodies are present in infection and then disappear with treatment making it easy to detect reinfection

Question 25

Meaning of VDRL

Answer 25

Veneral Disease Research Laboratory

Question 26

Serologic principle for VDRL

Answer 26

flocculation

Question 27

flocculation vs direct agglutination

Answer 27

Flocculation causes the antigen substance to be cloudy due to added substances that enhance the visibility of the reaction

Question 28

VDRL | - testing procedure

Answer 28

Cardiolipin antigen and patients SERUM mixed on glass microscope slide to detect reagin antibodies (serum must be heat inactivated for 30 minutes at 56C prior to testing)

Question 29

VDRL | - test results read micro or macroscopically

Answer 29

microscopically

Question 30

VDRL | - Appearance of reactive, weakly reactive, and non-reactive controls

Answer 30

Reactive: distinctive chunks Weakly Reactive: smaller chunks Nonreactive: cloudy

Question 31

Meaning of RPR

Answer 31

Rapid Plasma Reagin

Question 32

RPR | - serologic principle

Answer 32

flocculation

Question 33

RPR | - procedure

Answer 33

uses cardiolipin-lecithen-cholesterol antigen with carbon particles.

Question 34

RPR | - observed micro or macroscopically

Answer 34

macroscopically

Question 35

RPR | - appearance of reactive, weakly reactive, and non-reactive controls

Answer 35

Reactive: big darker chunks Weakly Reactive: smaller chunks with hazy background Nonreactive: clear and/or swirling tail

Question 36

VDRL v.s RPR | - sensitivity, specificity, and ease of performance

Answer 36

Have about the same sensitive and specificity for testing serum. RPR is NOT approved for CSF testing. - easier to do RPR because you have to heat inactivate

Question 37

VDRL v.s. RPR | - significance of a weakly reactive result

Answer 37

May be due to prozone with an increased amount of antibody present

Question 38

VDRL and RPR | - further testing for reactive or weakly reactive

Answer 38

must be tested quantitatively by the VDRL/RPR test and then confirmed by a treponema antibody detection method

Question 39

What is the only syphilis assay approved for testing spinal fluid?

Answer 39

VDRL